The present invention is directed to a weight measuring apparatus and more particularly to a method for calibrating a weighing scale so as to meet Federal standards concerning the accuracy of the scale for measuring weights placed on the scale.
Weighing scales are found in supermarkets or the like for weighing produce or other merchandise items and must meet stringent requirements as to performance and cost. The scales must be accurate enough to satisfy public weights and measures authorities. These requirements are usually met at the time the scale is manufactured by means of a standard calibrating procedure which includes setting switches representing the scale output upon the application of a standard weight and when no weight is applied. After the switches are set, the location of the switches is then sealed. As disclosed in the above cited co-pending application, Ser. No. 868,925, a check-out system includes a scale mounted within a check-out counter. It was found in some instances that once a calibrated scale was mounted within the check-out counter, it went out of calibration due to the temperature found within the counter. If the scale was removed, it was found to be within the required calibrated range. It was thus required that the recalibration of the scale take place within the check-out counter.
It is therefore a principal object of this invention to provide a method for recalibrating a weighing scale mounted within an enclosure which has been calibrated and sealed which is simple in its operation and can be accomplished in a minimum amount of time.